Potentially no blasting caps needed for a big boom in this situation.
Being in the engine compartment would increase the volatility of many explosive compounds, and an explosion could easily be set off by application of sufficient pressure from a collision. It would be entirely possible for a fender-bender to become a fireball, but we have no information on the nature of the explosive itself, nor its placement within the engine compartment, so this is purely speculative.

That being said, dogs can be trained a zillion different ways without utilizing non-CIA public assets. I can't imagine how many training scenarios I could create before getting down to school buses...

This is literally playing with fire.

Oh, you "left them on the bus," did you? A likely story, CIA! Next time you'll tell me a dog ate your explosives!

This is the third time this month. I know you can do better than this, CIA. Now take this progress note home and have your parents sign it, then bring it back tomorrow, or you're looking at a week of ISS.

The CIA should have played it off as an April Fool's joke.

I couldn't focus properly after hearing her refer to the speaker as "Suzahn" so I'm not real sure what all of this is about.